Passenger seats for use in an aerospace environment often have components constructed from light-weight materials such as aluminum, plastics, and composites. For example, a passenger seat may include a backrest frame formed from one of these light-weight materials. The backrest frame of the passenger seat may support other parts of the passenger seat (e.g., a back plate, cushioning, entertainment system, brackets, etc.). These other parts may be attached to the backrest frame using fasteners such as screws, inserts, rivets, etc. Use of such fasteners may damage and/or weaken the backrest frame. To account for such anticipated damage and/or weakening, the backrest frame may be designed to have increased strength, which often comes with increased weight. This increased weight attributable to the backrest frame may be undesirable; especially in commercial airline applications, where many seats are included in each aircraft.
When seated in the passenger seat, good support of the lumbar area of a passenger's back is important for proper spine alignment and overall comfort. Proper spine alignment corresponds to the natural curve of one's spine. This natural curve can vary drastically from one passenger to the next. In an attempt to provide lumbar support for passengers with different spine characteristics (e.g., different natural curves), passenger seats have been developed that include blow-up pillows, movable cushions, and bending plates. Such lumbar support systems, however, may be undesirable in an aerospace environment because of their added weight and high space requirements. In addition, such solutions may lack the versatility to provide proper lumbar support to a majority of passengers.
Additionally, the natural curve of the passenger's spine changes as the passenger sits in different positions. For example, when the passenger is seated in the passenger seat in an upright position, the natural curve is more pronounced as compared to when the passenger is seated in the passenger seat in a reclined position. Adjusting a lumbar support system to account for the position of the passenger seat may be burdensome to the passenger (e.g., requiring operation of mechanical and/or electrical devices to deflate/inflate pillows, move cushions, or adjust bending plates) or altogether forgotten. This may lead to a reduction in the benefits associated with of lumbar support, and may lead to discomfort and/or injury from improperly configured lumbar support.